Datasheet
MCP79410/MCP79411/MCP79412
DS20002266E-page 16 2010-2013 Microchip Technology Inc.
6.0 CONTROL REGISTER
The Control register is used to enable additional
features of the RTCC, such as Alarms and MFP square
wave divider. This register also contains bits that can
be used to toggle the MFP pin and also allow the RTCC
to be driven by an external CMOS 32.768 kHz clock.
.
REGISTER 6-1: CONTROL REG 0X07
R/W-1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
OUT SQWE ALM1 ALM0 EXTOSC RS2 RS1 RS0
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set “0” = Bit is clear “X” = Bit is unknown
bit 7 OUT: Level of MFP Pin bit
This bit sets the logic level on the MFP pin when not using this as a square wave output. This pin is
open-drain.
1 = Pin is not asserted
0 = Pin is logic low – asserted
bit 6 SQWE: Square Wave Enable bit
Setting this bit enables the divided output from the crystal oscillator
1 = Enable square wave
0 = Disable square wave
bit 5 ALM1: Alarm 1 Enable bit
1 = Alarm 1 enabled
0 = Alarm 1 disabled
bit 4 ALM0: Alarm 0 Enable bit
1 = Alarm 0 enabled
0 = Alarm 0 disabled
bit 3
EXTOSC: External Oscillator Input bit
1 = Enable RTCC X1 pin to be driven by external 32.768 kHz source
0 = Disable external 32.768 kHz input.
bit 2
RS2: Digital Trimming/Digital Calibration Mode bit
This bit is used to switch between Digital Trimming and Digital Calibration mode
1 = Enable the Digital Calibration mode. Calibration signal appears on CLKOUT if SQWE is set (64 Hz
nominal, see Section 8.4 “Digital Calibration Mode”).
0 = Disable the calibration output function, Digital trimming is enabled, see Section 8.3 “Digital Trim-
ming”.
bit 1-0
RS<1:0>: CLKOUT Divider bits
Sets the internal divider for the 32.768 kHz oscillator to be driven to the CLKOUT. The following
frequencies are available. The output is responsive to the Calibration register, see Section 3.4 “MFP
(Multifunction Pin)”.
- 00 – 1 Hz
- 01 – 4.096 kHz
- 10 – 8.192 kHz
- 11 – 32.768 kHz
Note 1: When RS2 is set to enable the calibration output function, the RTCC counters will continue to increment.